Various arrangements for raising or lowering boats at a pier having existed in the prior art. However, such arrangements have been burdened by numerous disadvantages.
Notably, such prior art arrangements have been overly complicated to assemble, and have involved the employment of an excess of hardware. In addition, such arrangements of the prior art have not been adjustable, and thus such arrangements have not been suitable for each and every pier piling situation encountered. Moreover, such arrangements have not been adjustable to the point where boats of different beams (widths) are accommodated.
Furthermore, the design of such prior art arrangements has been such as to place an excessive force on pier pilings on which the arrangement is mounted so that, once the lifting procedure begins or once the lifting procedure has been carried out a certain number of times, a stress failure of the pier pilings has developed, resulting in damage to the boat being lifted and possible injury to the individuals participating in the boat lifting operation.
The following U.S. Pat. Nos. are considered to be representative of the prior art relative to the invention disclosed herein: 3,109,185; 3,218,034; 3,289,627; 3,360,144; 3,804,263; 3,961,713; 3,967,570; 4,109,896; 4,139,110; 4,627,377; 4,637,770; 4,686,920; 4,699,075; and 4,763,593.